1. Field of the Invention
The present invention relates to a technique for collecting performance information of a computer capable of executing more than one application software.
2. Description of the Related Art
Owing to a recent advance of telecommunication networks, a system for providing many people with a service is usually built in a server. The system includes a business system for supporting a business in a business enterprise for example. A system for providing a service for general users are usually built in a server provided on a Web site.
An important provision of a service is a capability of appropriately providing it. Accordingly, the actual practices include a collection of information indicating a usage condition of resources possessed by a server (e.g., a computer), as performance information, and a monitoring of it, in order to maintain a quality of service. The collection and monitor of the performance information makes it possible to respond so as to make the service available continuously and comfortably. The performance information includes a CPU usage rate, a memory usage volume and a disk usage space for example.
The performance information has conventionally been collected at a predetermined fixed time interval so as to prevent a data volume obtained by the collection from becoming enormous. The collection of data at a predetermined fixed time interval, however, is faced with a possibility of not being able to collect performance information at the time of a condition affecting a quality of service. Such a possibility is reduced by shortening such a predetermined fixed time interval. Shortening the time interval, however, proportionately increases a load required for the collection of the performance information, resulting in degrading performance of a server. Because of this, some of conventional performance information collection apparatuses are configured to change a time interval (or timing) for collecting performance information dynamically according to a resource usage condition as the one noted in a Laid-Open Japanese Patent Application Publication No. 2005-4336. A dynamic change of the time interval makes it possible to collect the performance information by shortening the time interval in a condition requiring the collection of the performance information at a shorter time interval.
A reduction of a quality of service usually occurs under a condition of a high resource usage rate. Consequently, the conventional performance information collection apparatus noted in the Laid-Open Japanese Patent Application Publication No. 2005-4336 is configured to collect performance information at a shorter time interval as a resource usage rate increases. Shortening the time interval, however, corresponds to increasing a load required for collecting the performance information under the condition of a heavy load. In consideration of this, the conventional performance information collection apparatus noted in the Laid-Open Japanese Patent Application Publication No. 2005-4336 is configured to select a kind of performance information which makes a collection time interval longer from among the target performance information, thereby suppressing an increase of a load required for collecting the performance information under such a condition.
As described above, an expansion of a collection time interval increases a possibility of being unable to collect the necessary performance information. The load required for collecting the performance information had desirably better not affect a quality of service. Because of this, it is conceptually important to carryout the collection of performance information from a view point other than a resource usage rate.
The buildup of a system in a server is accomplished by developing application software (simply “application” hereinafter), that is, a program to be executed by a computer used as a server, and making the application executable, regardless of a kind of the system. This is transparent to a configuration of whether or not connecting a plurality of servers by way of a telecommunication network. A common Web site is configured to connect a plurality of servers.
A resource required for carrying out an application differs with application. Also, the execution frequency or the importance differs with application. Such differences exist between applications. Because of this, the collection of performance information by focusing on an application is also considered to be important.